AudioCodes Mediant 1000B User Manual page 272

use a specific routing server. Alternatively, a single routing server can be employed and
used for all devices ("stateful" routing server).
The device automatically updates (sends) the routing server with its' configuration topology
regarding SIP routing-related entities (Trunk Groups, SRDs, SIP Interfaces, and IP Groups)
that have been configured for use by the routing server. For example, if you add a new IP
Group and enable it for use by the routing server, the device sends this information to the
routing server. Routing of calls associated with routing-related entities that are disabled for
use by the routing server (default) are handled only by the device (not the routing server).
In addition to regular routing, the routing server functionality also supports the following:

Alternative Routing: If a call fails to be established, the device "closest" to the failure
and configured to send "additional" routing requests (through REST API -
"additionalRoute" attribute in HTTP Get Route request) to the routing server, sends a
new routing request to the routing server. The routing server may respond with a new
route destination, thereby implementing alternative routing. Alternatively, it may enable
the device to return a failure response to the previous device in the route path chain
and respond with an alternative route to this device. Therefore, alternative routing can
be implemented at any point in the route path. If the routing server sends an HTTP
404 "Not Found" message for an alternative route request, the device rejects the call.
If the routing server is configured to handle alternative routing, the device does not
make any alternative routing decisions based on its alternative routing tables.

Call Status: The device can report call status to the routing server to indicate whether
a call has successfully been established and/or failed (disconnected). The device can
also report when an IP Group (Proxy Set) is unavailable, detected by the keep-alive
mechanism, or when the CAC thresholds permitted per IP Group have been crossed.
For Trunk Groups, the device reports when the trunk's physical state indicates that the
trunk is unavailable.

Credentials for Authentication: The Routing Server can provide user (e.g., IP Phone
caller) credentials (username-password) in the Get Route response, which can be
used by the device to authenticate outbound SIP requests if challenged by the
outbound peer, for example, Microsoft Skype for Business (per RFC 2617 and RFC
3261). If multiple devices exist in the call routing path, the routing server sends the
credentials only to the last device ("node") in the path.

To configure routing based on Routing server:
1. For each configuration entity (e.g., IP Group) that you want routing done by the routing
server, configure the entity's 'Used By Routing Server' parameter to Used.
2. Configure an additional Security Administrator user account in the Local Users table
(see ''Configuring Web User Accounts'' on page 71), which is used by the routing
server (REST client) to log in to the device's management interface.
3. Configure the address and connection settings of the routing server, referred to as a
Remote Web Service and HTTP remote host. You must configure the 'Type'
parameter of the Remote Web Service to Routing.
4. SBC Calls: In the IP-to-IP Routing table, configure the 'Destination Type' parameter of
the routing rule to Routing Server (see Configuring SBC IP-to-IP Routing Rules on
page 643).
5. Gateway Calls: Enable routing based on routing server, by configuring the
GWRoutingServer parameter to 1.
User's Manual
Mediant 1000B Gateway and E- SBC
272 Document #: LTRT-27044